Hermetic container for frozen food preservation and microwave oven thawing

ABSTRACT

A food container, particularly a hermetic container for preserving foods in refrigerators and freezers and for thawing in a microwave oven, comprising a base body with which a lid can be associated hermetically, the lid forming a groove that is open toward the edge of the base body. The lid has a substantially rigid central portion with which a substantially elastic peripheral portion that forms the groove is associated. The central portion reaches, in a radial direction, no further than the region delimited by the edge.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a food container, particularly ahermetic container for preserving foodstuff in refrigerators andfreezers and for thawing the foodstuff in a microwave oven.

[0002] As is known, food containers are already commercially availablewhich are devised specifically to be used in refrigerators and freezersand are manufactured so that they can be placed in a microwave oven toheat the product contained therein.

[0003] During heating in microwave ovens, it is necessary to remove thelid of hermetic containers in order to avoid its violent removal due tothe pressure of the steam generated during the thawing and subsequentheating of the food.

[0004] This fact causes two kinds of drawback: the first one is that itis necessary to perform a first thawing step in order to allow to removethe lid, and the second one is that heating the container without a liddoes not prevent the food from spattering out of the container.

[0005] The prior art solutions have failed to solve the problemadequately and in many cases have led to the provision of complicatedstructures that nonetheless failed to optimize the problem.

SUMMARY OF THE INVENTION

[0006] The aim of the present invention is to solve the above mentioneddrawbacks by providing a food container that allows to thaw and heatfood contained in the containers in a microwave oven without having tofirst remove the lid, thus allowing a single transfer from the freezerto the microwave oven, reducing the thawing time required, byeliminating the pause for thawing at ambient temperature and improvingthe general processing conditions, since outward spattering isprevented.

[0007] Within this aim, an object of the present invention is to providea food container that can be placed in a microwave oven for thawing yetis capable of achieving a perfect hermetic seal, preventing the mixingof odors produced by different foods from mixing inside therefrigerator.

[0008] Another object of the invention is to provide a container thatallows optimum adhesion for the closure of the lid on the container byperforming particularly simple operations.

[0009] Another object of the invention is to provide a food containerthat thanks to its particular constructive characteristics is capable ofgiving the greatest assurances of reliability and safety in use.

[0010] This aim and these and other objects that will become betterapparent hereinafter are achieved by a food container, particularly ahermetic container for preserving foodstuff in refrigerators andfreezers, according to the invention, comprising a base body with whicha lid can be associated hermetically, such lid forming a groove that isopen toward the edge of the base body, characterized in that said lidhas a substantially rigid central portion with which a substantiallyelastic peripheral portion that forms the groove is associated, saidcentral portion reaching, in a radial direction, no further than theregion delimited by said edge.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Further characteristics and advantages of the present inventionwill become better apparent from the following detailed description of apreferred but not exclusive embodiment of a food container, particularlya hermetic container for preserving food in refrigerators and freezers,illustrated by way of non-limitative example in the accompanyingdrawings, wherein:

[0012]FIG. 1 is a schematic sectional view, taken along a transverseline, of a food container according to the invention;

[0013]FIG. 2 is a sectional view of multiple stacked base bodies of thecontainer;

[0014]FIG. 3 is an exploded sectional view of the detail of theconnection between the lid and the base body;

[0015]FIG. 4 is a sectional view of the container in the closedposition;

[0016]FIG. 5 is a schematic view of the deformation undergone by the lidwhen the product in the container is heated.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] With reference to the figures, the food container, particularly ahermetic container for preserving food in refrigerators and freezers,according to the invention, generally designated by the referencenumeral 1, comprises a base body 2 advantageously made of a plasticsthat is compatible for use with foodstuffs.

[0018] As shown in cross-section, the base body 2 has a lateral surfacethat is advantageously inclined outwardly and has a substantiallysinusoidal transverse cross-section.

[0019] Satin-finished bands and clear bands can be present alternatelyon the walls 3 in order to better view the contents of the container.

[0020] Advantageously, the curved portions that define the sinusoidalpath have internal radii of curvature Ri and external radii of curvatureRe that are substantially identical one another.

[0021] Proximate to the upper part of the side wall there is aflange-like rim, designated by the reference numeral 5, that affectsperipherally the entire base body 2 and acts as a stiffening element.

[0022] A lid 10 can be coupled to the base body 2 and formsperimetrically a groove 11 that is open toward the base body 2.

[0023] In greater detail, the lid 10 has a substantially rigid centralportion 12 that ends peripherally with a protruding tab 13 on which aperipheral portion 20 is applied, such portion forming the groove 11 andbeing advantageously made of elastically flexible material.

[0024] A particularity of the invention is that the tab 13, andaccordingly the rigid portion of the lid 10, reaches or extends in aradial direction no further than, or substantially up to, the regiondelimited by the edge 30 of the base body.

[0025] The edge 30 of the base body is substantially straight and ispreferably provided on the continuation of the lateral surface of thebase body, with an inclination comprised between 0 and at the most 10°.

[0026] The peripheral portion, which is made of elastically flexiblematerial, defines in practice an inner lip 21 and an outer lip 22,between which the groove 11 is located; the inner lip mates with theinner surface, achieving an excellent hermetic seal, in cooperation withthe outer lip 22, which mates both with the outer surface of the edge 30and with the flange rim 5 that engages by contact the lower edge 22 a ofthe outer lip.

[0027] This arrangement provides an optimum hermetic seal, since itproduces a synergistic effect between the elastic peripheral portion andthe rigid central portion, which in conditions of normal use increasesthe adhesion that occurs between the lips 21 and 22 and the edge 30.

[0028] It should also be noted that the radial end of the tab 13 reachesat least one third of the thickness of the edge 30, and therefore therigid portion can surmount, in practice, the edge that enters the groove11 but can never protrude radially with respect to the outside and theinside.

[0029] Thereby the particular shape of the tab 13, which has a concavitydirected toward the base body, when the container is placed in themicrowave oven, the pressure generated inside the container applies anoutward thrust to the rigid portion or central portion of the lid 10,which causes an oscillation of the tab 13 that surmounts the inner lip21, which is forced to rotate, moving away from the inner surface of theedge 30, thus weakening the seal.

[0030] Likewise, due to this deformation, the outer lip 22 that engagesan upper portion of the edge 30 splays outward, thus forming a sort ofreduced seal region that allows to vent outward the steam that acts as alubricant on the resting region and, by venting gradually out, avoidsthe expulsion of the lid.

[0031] It should be added to the above that on the edge 30, above theregion affected by the rim 5, it is possible to provide through holes 40arranged at a distance from the free border of said edge that is shorterthan the depth of the groove 11. The holes 40 are designed to furtherfacilitate the escape of steam during heating and the escape of air inthe initial steps of the depressurization of the container, before it isplaced in the refrigerator, such depressurization occurring by applyingto the lid a pressure from the outside toward the inside.

[0032] The thicknesses of the inner lip and outer lip, which are made ofelastically flexible material, can have different mutual ratios,although the best results have been obtained by using substantiallyidentical thicknesses.

[0033] In practical operation, as shown in FIG. 5, the steam, byapplying force to the inner surface of the lid, forces it to deforminward the tab 13, separating the inner lip 21 from the inner edge 30,allowing the steam to be interposed between the two surfaces,lubricating them and facilitating the lifting of the lid withoutexplosion.

[0034] It is therefore evident from the above description that theinvention achieves the intended aim and objects; the fact is furtherstressed that the particular mutual arrangement of the rigid parts andthe soft parts of the cover allows to obtain a gradual venting of thesteam without having to resort to the use of valves and without riskingany violent expulsions of the lid or even explosions.

[0035] The invention thus conceived is susceptible of numerousmodifications and variations, all of which are within the scope of theappended claims.

[0036] All the details may further be replaced with other technicallyequivalent elements.

[0037] The materials used, so long as they are compatible with thespecific use, as well as the contingent shapes and dimensions, may beany according to requirements.

[0038] The disclosures in Italian Patent Application No. MI2001A001610from which this application claims priority are incorporated herein byreference.

What is claimed is:
 1. A hermetic food container for preserving frozenfoodstuff and for thawing the frozen foodstuff in a microwave oven,comprising: a base body having an edge delimiting an edge regionthereof; a lid hermetically connectable to said base body; a grooveprovided at said lid that is open toward the edge of said base body,wherein said lid comprises a substantially rigid central portion and asubstantially elastic peripheral portion that forms said groove, whichis connected to said rigid central portion, with said rigid centralportion extending, in a radial direction, no further than the edgeregion delimited by said edge.
 2. The container of claim 1, wherein saidbase body comprises lateral walls inclined outwardly and having, intransverse cross-section, a substantially sinusoidal surface shape. 3.The container of claim 2, wherein said lateral walls comprise, onlateral surfaces thereof, satin-finished bands alternated with clearbands.
 4. The container of claim 2, wherein said sinusoidal surfaceshape is constituted by curved portions that have internal radii ofcurvature substantially equal to external radii of curvature thereof. 5.The container of claim 2, wherein said base body is provided with anouter rim, said edge of said base body being substantially straight andarranged on continuation of said lateral walls, proximate to said edge.6. The container of claim 5, wherein said substantially rigid centralportion is provided peripherally with a protruding tab on which saidperipheral portion made of flexible material is applied.
 7. Thecontainer of claim 6, wherein said peripheral portion made of flexiblematerial comprises an inner lip and an outer lip that delimit saidgroove, said inner lip being hermetically connectable with an innersurface of said edge and said outer lip being connectable with an outersurface of said edge and with said rim.
 8. The container of claim 7,wherein said tab is delimited by a radial end thereof that extendsradially for a distance being at least one third of a thicknessdimension of said edge.
 9. The container of claim 8, wherein said tabcomprises a concavity that is directed toward said base body.
 10. Thecontainer of claim 8, wherein upon generation of pressure inside saidcontainer during heating, said tab is provided so as to oscillate todetermine inward oscillation of said inner lip of said groove andoutward oscillation of said outer lip.
 11. The container of claim 10,further comprising at least one through hole located on said edge ofsaid base body, above said rim and at a distance from a free border ofsaid edge that is shorter than a depth extension of said groove.